RFR: 8303401: Add a Vector API equalsIgnoreCase micro benchmark [v8]

[Paul Sandoz]

On Wed, 1 Mar 2023 17:48:46 GMT, Eirik Bjorsnos <duke at openjdk.org> wrote:

>> This PR suggests we add a vectorized equalsIgnoreCase benchmark to the set of benchmarks in `org.openjdk.bench.jdk.incubator.vector`. This benchmark serves as an example of how vectorization can be useful also in the area of text processing. It takes advantage of the fact that ASCII and Latin-1 were designed to optimize case-twiddling operations.
>> 
>> The code came about during the work on #12632, where vectorization was deemed out of scope.
>> 
>> Benchmark results:
>> 
>> 
>> Benchmark                             (size)  Mode  Cnt     Score   Error  Units
>> EqualsIgnoreCaseBenchmark.scalar          16  avgt   15    21.575 ± 0.365  ns/op
>> EqualsIgnoreCaseBenchmark.scalar          32  avgt   15    43.199 ± 2.786  ns/op
>> EqualsIgnoreCaseBenchmark.scalar          64  avgt   15    71.389 ± 0.891  ns/op
>> EqualsIgnoreCaseBenchmark.scalar         128  avgt   15   146.827 ± 1.115  ns/op
>> EqualsIgnoreCaseBenchmark.scalar        1024  avgt   15  1062.759 ± 9.331  ns/op
>> EqualsIgnoreCaseBenchmark.vectorized      16  avgt   15    21.483 ± 0.121  ns/op
>> EqualsIgnoreCaseBenchmark.vectorized      32  avgt   15    10.538 ± 0.125  ns/op
>> EqualsIgnoreCaseBenchmark.vectorized      64  avgt   15    13.182 ± 0.177  ns/op
>> EqualsIgnoreCaseBenchmark.vectorized     128  avgt   15    19.192 ± 0.421  ns/op
>> EqualsIgnoreCaseBenchmark.vectorized    1024  avgt   15    92.521 ± 3.494  ns/op
>
> Eirik Bjorsnos has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add whitespace after if

Marked as reviewed by psandoz (Reviewer).

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PR: https://git.openjdk.org/jdk/pull/12790